Target holding control unit

ABSTRACT

A multitarget holding control unit for collecting specimens from a particle accelerator arrangement normally operating under a vacuum condition to enable performance studies in the hypervelocity impact phenomena of accelerated small solid particles having a size on the order of 10 4 cm. in diameter. A cup-shaped housing has its base secured to the hub of a centrally apertured adapter for sealed connection to a particle accelerator arrangement. A plurally apertured cover, sealingly secured to an outward face of the cup peripheral sidewall, supports respective target plate shafts, index means and control knob. Within the completely sealed unit, a plurality of overlapping and longitudinally spaced target plates are arranged on their shafts such that a peripheral target space on each target plate disc can be simultaneously aligned with the adapter aperture. Each of the peripheral targets on each plate is provided with an electrical conductive means to collect electrical charges carried by particles and controllingly delivered through the adapter aperture to the peripherally mounted target.

United States Patent [72] Inventor Abraham L. Korr Philadelphia, Pa. [2 I Appl. No. 850,129 [22] Filed Aug. I4, 1969 [45] Patented May 4, 1971 [73] Assignee The United Stateso! America as represented by the Secretary of the Army [54] TARGET HOLDING CONTROL UNIT 6 Claims, 4 Drawing Figs.

[52] U.S.Cl 73/12 [51] G0ln 3/08 [50] Field ofSearch 73/l2,28, 170

[56] References Cited 7 UNITED STATES PATENTS 3,130,575 4/1964 Rogers 73/12 3,222,925 12/1965 Kracke et al 73/170 3,267,720 8/1966 Escallier et al. 73/ 12 3,343,400 9/1967 Rogers et al. 73/ l 2' Primary Examiner-Charles A. Ruehl Att0rneysl-larry M. Saragovitz, Edward .I Kelly, Herbert Berl and S. Dubroff ABSTRACT: A multitarget holding control unit for collecting specimens from a particle accelerator arrangement normally operating under a vacuum condition to enable performance studies in the hypervelocity impact phenomena of accelerated small solid particles having a size on the order of [0 cm. in diameter. A cup-shaped housing has its base secured to the hub of a centrally apertured adapter for sealed connection to a particle accelerator arrangement. A plurally apertured cover, sealingly secured to an outward face of the cup peripheral sidewall, supports respective target plate shafts, index means and control knob. Within the completely sealed unit, a plurality of overlapping and longitudinally spaced target plates are arranged on their shafts such that a peripheral target space on each target plate disc can be simultaneously aligned with the adapter aperture. Each of the peripheral targets on each plate is provided with an electrical conductive means to collect electrical charges carried by particles and controllingly delivered through the adapter aperture to the peripherally mounted target.

SIA

lZ- i l5 s l3 s T' i4 64- a 7 16 26 Ag B-23 l9 l7 Patented May 4, 1971 2 Sheets-Sheet 2 INVENTOR. ABRAHAM L. KORR BY" Miam M I W ATTORNEYS.

have had to use statistical techniques in establishing a relationship of particle-to-target impact phenomena because of the excessive down time associated with the changing of targets that required breaking of the vacuum seals.

It is an object of the invention to provide a multitar'get control mechanism in which the amount of down time is minimized since a multiplicity of targets may be indexed directly in the path of particle beam without breaking the vacuum.

Another object of the invention is to provide such a target control mechanism in which a maximum number of targets in a minimum space can be operatively positioned in line with a particle beam under a vacuum condition.

These and other objects, features and advantages will become more apparent from the following description and accompanying drawings in which:

FIG. 1 is a top plane view of the target holding control unit, with certain parts removed, embodying the principles of the invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is a plane view of one of the target discs.

FIG. 4 is an exploded perspective view of the cup-shaped housing and one of the contact mountings therefor.

The target holding control unit, shown generally at (FIG. I) has a cup-shaped housing, the base portion 11 of which has a threaded central aperture and a surrounding O-ring seal 12 (FIG. 2) in an external surface of the base for sealing securement upon the threaded hub portion 13 of the centrally apertured adapter 14. The outer face of the adapter contains a suitable O-ring seal 15 such that the vacuum condition within a particle accelerator drift tube arrangement (not shown) may be maintained when the adapter is appropriately secured thereto by peripheral screws 16.

The peripheral sidewall I7 of the cup housing is substantially of a circular contour with one area provided with an enlargement or protuberance 18 containing a tapped portion 19 of a transverse passage 20 through which are passed electrical impulse supplying cable wires 20A carried by an appropriately sealed plug or vacuum seal fitting I9A securable in tapped opening 19. The end face of the sidewall 17 contains a relatively large O-ring 21 for sealing against the cover member 22 when secured thereagainst by fastening screws 23 which are circumferentially spaced along the cover periphery and mounted in suitably tapped recesses 24 (FIG. 1) formed in the sidewall 17.

A plurality of disc-shaped target plates 26, 27, 28, each secured to its shaft 30, 31, 32 which extends through an aligned corresponding pair of cover aperture and central aperture of a respective index plate 33 (FIG. 2) that is seated or secured in a corresponding recess provided therefor in the cover external face. Each target plate shaft has a pair of Iongitudinally spaced O-rings 34 predeterrninedly positioned to sealingly engage the respective journal apertures of the cover and index plate, carries suitable bushing means 31A on either side of its target plate to longitudinally space the target plates with portions thereof in an overlapping position such that a peripheral target space 36 on each disc can be simultaneously aligned with the central passage of adapter 14, and is secured to its respective control knob 37 preferably by a conventional locking or setscrew 38. Each index plate has a plurality of arcuate recesses 38A, corresponding to the target spaces 36 on its target plate, that can be successively engaged by the respective spring biased ball detent 40 appropriately retained by screw 41 threadedly engaging one end of the knob aperture longitudinally extending therethrough substantially parallel to its target shaft. Each peripheral target space or disc aperture 36, except one, an oversized hole (FIG. 4), on each of plates 26 and 27, has seated thereon a metallic target 42 (FIG. 3). Each target 42 is insulated and in electrical contact through a corresponding elongated insulated metallic member 43 with an insulated metallic ring 44 which is suitably secured to the respective target disc.

Tapped recesses 45, 46 (FIG. 4) in the housing base 11 are aligned longitudinally with corresponding apertures 47, 48 of an insulation spacer 49 and respective apertures 50, 51 of contact base 52. Screw 53 and its flanged tubular insulator 54 align the opening 55 of spring contact 56 with apertures 50, 47 and screw 53 secures the insulated contact arrangement to the base tapped recess 45 with the spring contact return bend 57 in sliding engagement with the corresponding metallic ring 44 (FIG. 3) of target disc 27. An appropriate screw (not shown) passing through apertures 51, 48 secures in base tapped recess 46 to firmly position the insulated contact base 52 which has an appropriate pair of terminal mounting apertures 58, 59 to connect suitable end portions of wire means 20A (FIG. 1) leading from cable 208.

Similar contact mountings are provided such that corresponding spring contact return bends 57 slidably engage respective metallic rings 44 for target discs 26 and 28. The insulation spacer 49 of the contact mounting for disc 26 is secured in an appropriate recess 60 provided in housing base 11 such that the desired longitudinal position of the associated elements is attained when the contact mounting is secured to the base tapped recesses 61, 62. The insulation spacer 49 employed with the contact mounting for disc 28 preferably is of larger thickness, or a pair of such spacers may be used, so as to obtain proper longitudinal positioning of the associated elements.

Each control knob 37 has its reduced lateral surface provided with appropriate peripherally spaced indicia means 37A (FIG. 2) that correspond to respective target spaces 36, 36A on the associated target plate. Preferably, an index or target designating mark 63 is provided at selected positions on the external surface of the cover 22 adjacent each of the corresponding control knob indicia means 37A. Preferably, each indicia mark 37A includes a numerical character, and a selected one on each knob corresponding to target discs 26, 27 is employed to designate their respective oversized hole 36A. This structure provides the means for control positioning of the predetermined individual targets 42 or spaces 36A along the centerline 64 of the particle beam operatively passing through the adapter aperture, without destroying the desired vacuum seal condition within the target holder unit and a particle accelerator drift tube or the like to which it can be satisfactorily attached.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

I. In a target holding control unit having a centrally apertured adapter securable to a particle accelerator arrangement, said adapter having a face of one end thereof provided with an O-ring seal, the other end of the adapter having an externally threaded hub portion,

a cup-shaped housing having a centrally apertured base secured to said adapter hub, said base having an external surface abutting said adapter and carrying an O-ring seal adjacent the base aperture,

a plurally apertured cover sealingly secured to an outward face of the cup peripheral sidewall,

a plurality of shafts each extending through a corresponding cover aperture and having a control knob secured to each shaft outer end,

a disc-shaped target plate secured to each shaft within the housing and having a group of peripherally located tar gets for collecting particle specimens, each target plate being longitudinally spaced from the others and having a portion overlapping portions on the other target plates, such that a target space on each disc can be simultaneously aligned with said adapter aperture all target plates except one adjacent said cover having at least one peripheral target space being formed with a through passage, and v means includes an index plate secured in a corresponding recess provided in the external face of said cover, each index plate having a central aperture in alignment with a respective cover aperture and a plurality of arcuate recesses corresponding to the target spaces of the respective target plate, each of said knobs having an aperture extending parallel to and offset from its respective shaft and a spring-biased ball in each knob aperture for successively engaging the arcuate recesses of the corresponding index plate, and each of said target plate shafts having a pair of longitudinally spaced O-ring seals respectively contacting the aperture walls of its index plate and recessed cover portionv 5. The structure of claim 4 wherein each control knob has a reduced annular peripheral surface adjacent its index plate, and indicia means on said reduced surface and correspondingly positioned relative to the arcuate recesses of the respective index plate.

6. The structure of claim 5 in which a target designating mark is provided on said cover adjacent each of said corresponding control knob indicia means. 

1. In a target holding control unit having a centrally apertured adapter securable to a particle accelerator arrangement, said adapter having a face of one end thereof provided with an O-ring seal, the other end of the adapter having an externally threaded hub portion, a cup-shaped housing having a centrally apertured base secured to said adapter hub, said base having an external surface abutting said adapter and carrying an O-ring seal adjacent the base aperture, a plurally apertured cover sealingly secured to an outward face of the cup peripheral sidewall, a plurality of shafts each extending through a corresponding cover aperture and having a control knob secured to each shaft outer end, a disc-shaped target plate secured to each shaft within the housing and having a group of peripherally located targets for collecting particle specimens, each target plate being longitudinally spaced from the others and having a portion overlapping portions on the other target plates, such that a target space on each disc can be simultaneously aligned with said adapter aperture all target plates except one adjacent said cover having at least one peripheral target space being formed with a through passage, and means associated with each knob for indexing the respective target spaces of its disc.
 2. The structure in accordance with claim 1 wherein each target plate has an electrical conductive contact ring having radially outward extending portions terminating in a corresponding circular contact member defining the respective targets.
 3. The structure of claim 2 wherein said housing peripheral sidewall has a radial passage containing a vacuum seal fitting for accommodating wire means adapted to provide an electrical impulse source for said contact ring.
 4. The structure of claim 1 wherein each of said indexing means includes an index plate secured in a corresponding recess provided in the external face of said cover, each index plate having a central aperture in alignment with a respective cover aperture and a plurality of arcuate recesses corresponding to the target spaces of the respective target plate, each of said knobs having an aperture extending parallel to and offset from its respective shaft and a spring-biased ball in each knob aperture for successively engaging the arcuate recesses of the corresponding index plate, and each of said target plate shafts having a pair of longitudinally spaced O-ring seals respectively contacting the aperture walls of its index plate and recessed cover portion.
 5. The structure of claim 4 wherein each control knob has a reduced annular peripheral surface adjacent its index plate, and indicia means on said reduced surface and correspondingly positioned relative to the arcuate recesses of the respective index plate.
 6. The structure of claim 5 in which a target designating mark is provided on said cover adjacent each of said corresponding control knob indicia means. 